Control apparatus



Jan. 12, 1932.

A. JOHANSSON CONTROL APPARATUS Filed Nov. 19, 1927 3 Sheets-Sheet 2ATTEDRNEY 3 Sheets-Sheet 3 Filed Nov. 19. 1927 M m 6 T0 w Wf w H ATORNEY Patented Jan. 12, 1932 warren STATES PATENT OFFICE .A N DERSJOI-IANSSON, OF STACKEBO-HID, SWEDEN, ASSIGNOR- T WESTINGHOUSE ELEC-TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTROL APPARATUS Application filed November 19, 1927. Serial No.234,422.

, My invention relates generally to control apparatus and moreparticularly to timelimit, snap-action switches.

The object of my invention generally stated is to provide a simple andreliable mechanically-operable limit-switch.

It is also an object of my invention to provide for positively actuatinga switch at predetermined intervals.

A furtherobject. of my invention is to provide for effectivelylubricating the actuating mechanism of a mechanically-operabletime-limit switch.

Another objeot of my invention is to pro,- vide for free movement of thedriving element of a limit-switch in the direction in which the switchis actuated without further actuation of the switch.

. Other objects of the invention will, in part, be obvious and will, inpart, appear heremafter;

The invention accordingly is disclosed in the embodiment thereof shownin the accompanying drawings and comprises the structural features, thecombination of elements and arrangement of parts which will beexemplified'in the construction hereinafter set forth, and the scope ofthe application which will be indicated in the claims.

For a more complete understanding of my invention, reference may be hadto the following detailed description taken in conjunction with theaccompanying drawings, in'

it is actuated in one direction and the opera-j 151011 of the switchesmav'be readily under stood from an examination of them.

As illustrated a casting or frame 1 is pro-L vlded to carry theswitch-mg 'mechanismfas well as other apparatus. A shaft 2 for carryingthe contact members is pivotally mounted in the frame in bearings 3 anda. A plurality of arms 5 to which contact members 6 are attached aremounted on the shaft 2 and the contact members 6 are disposed tocooperate with resiliently supported contact members? carried by theframe.

In order that the switch arms 5 may be moved'or actuated with a snapmotion an over-center spring snap action mechanism for operating. theswitch is provided.

For the purpose of maintaining positive contact pressure between thecontact mem here 6, carried by the arms 5, and the contact members 7,until the over-center spring snap action mechanism is actuated throughits position of unstable equilibrium, springs 7 are provided. As isshown, the springs are maintained in compression when the contactmembers 6 and 7 are closed (seeFig. When the contact arms 5fare actuatedin a counter-clockwise direction, as viewed from Fig. 3, the. springs 7will cause the contact members to turn about the shafts 8, wherebypositive contact pressure will be maintained between the contact members6 and 7 until the switch arms 5 have been actuated with a snap motion.The snap motion re sults as a consequence of the over-center springmechanism being actuated through its dead-center or position of unstableequilibriuml As will be observed, the contact members 6 and 7 are soshaped, that rolling contact is effected between them during both theclosing and opening operations of the switch mechanism.

With a view to oscillating the shaft 2 carrying the contacts 6 a leverarm 8 is provided, to one end of which a spring 9 is attached by meansof a link 10. The other end of the spring is connected by a link 11 anda bolt lla to a pivot crank member 12. In order to facilitate easypivotal motion between thelink 11 and the pinion 11a a roller bearingmember 13 is'provided as illustrated. The crank'member 12 ispivotallymounted on a shaft 1ft, which in turn is loosely mounted in a'bifurcated lever member 15 that is pivotally supported on the mainoperating shaft 16 of the traveling nut device. Where the shaft 14 issupported by the lever member 15, for the purpose of reducing friction,a pair of ball bearing members 17 are utilized, and in this particularswitch are held in place in the manner illustrated.

At the inner end of the crank member is a j aw-like ratchet member 19which is loosely mounted on the shaft 14 and disposed to engage the pawl37 on the traveling nut device to move the spring biasing mechanism backand forth, across the center line of the switch to cause the over-centerspring 9 to actuate the switch from one .position to the other. Thetraveling or floating nut mechanism 31 is provided for actuating thespring biasing mechanism, and is adapted to be adjusted to regulate thenumber of revolutions of the shaft required for each operation of theswitch mechanism. 7 Y

Thetraveling or floating nut mechanism has-a main operating shaft 16which is supported in the frame 1 by the bearings 21 and 22 disposed atopposite ends of the shaft. The central portion of the shaft 16 is provided with a threaded section 20 on which is mounted a pair of travelingor floating nuts 23 and 24 for the purposeyof actuating the travellingnut device. The floating or trav-' cling" nuts are divided in order togive a wide range of adjustment tothe traveling or floating nutmechanism.

At both ends of the threaded section 20 for the purpose of limiting thetravel of the threaded or floating nuts 23 and 24, are firmly secured apair of collars 25 and 26, respectively. Projections 27 and 28 areprovided on the collars 25 and 26 to cooperate with projections 29 and30, disposed on the traveling nuts 23 and 24. In order to hold.

the traveling nuts 23' and 24 against rotation with the main threadedshaft 16, a guide member is provided which consists of a hollowcylindrical casing member comprising an upper half section 32 and alower half section 33, which are held together loosely on the shaft 16by the bolts 34. The casing sections 32 and 33 are disposed to incasethe collars 25 and 26, the traveling nuts 23 and 24 and the threadedsection 20 of the shaft 16.

In the upper section 32 of the casing, a,

' member not shown). When the shaft 16 is rotated, the pawl 37 will beforced into engagement with the ratchet 19, when ing shaft 16 in adirection depending upon the direction of rotation of the shaft 16.

However, when one of the traveling nuts passes mto engagement with oneof the projections 27 or 28, on the stop collars 25 or 26, the casingwill be held in fixed relation with the shaft 16. This will cause thecasing or cylinder to rotate with the shaft 16, and the pawl member 37will impart sufiicient force to the ratchet member 19 to carry thespring biasing mechanism over the center of the switch and cause thespring 9 to snap the contact lever arm 8 to its opposite positionactuating the switching mechanism.

Should the element driving the operating shaft 16 continue to rotate inthe same direction after the switch has been operated the pawl member 37will merely strike the outer point 40 of the ratchet member 19displacing the spring a slight amount, neither injuring the spring norcausing the switch to be further operated. 1

It will thus be seen that the driving mechanism can travel afteroperation of the switch, without causing injury to the snap actionmechanism. WVhere my invention is employed for reversing the operationof a motor a the ratchet member and the spring biasing mechanism to theright and move the spring 9 over its dead center point as illustrated inFigs. 5, 6 and 7, respectively. ing contact will be maintained betweenthe contact members 6 and 7 because of the action of the springs 7,until after the spring 9 has passed over its center point, or positionof unstable equilibrium. (the center point is illustrated in Figs. 6 and7 Immediately thereafter, through the force present'in the tensionspring 9, the switch will be actuated with a snap motion into its othercircuit closing position.

In order to provide for automatic lubrication of the bearings 21 and 22,in which the ends of the shaft 16 are j ournalled, the cylindercomprising the half cylindrical sections 32 and 33 may be packed witha'suitable lubricant. the cylinder through a grease cup 16' dis-Positive. roll- Y The lubricant may be forced into posed at one end ofthe shaft 16. Lubricant from the grease cup 16 may be forced into thecylinder through a passageway i extending along the end of the shaftfromthe grease cup and terminating in the casing or cylinder.

As the tra. c ing nuts 23 and 24 move back and forth on the threadedportion of the shaft 1e, grease or lubricant will be squeezed out alongthe shaft to the bearings.

While I have illustrated described particular embo iment of myinvention, it intended that all matter herein set forth shall beinterpreted as illustrative and not in a limiting sense, sincemanifestly the same may be considerably varied without departing fromthe spirit I" the invention as set forth in the appended claims.

I claim as my invention:

1. In a switching device in combination, an over-center spring mechanismdisposed to actuate a switch, and an actuating mechanism thereforcomprising a rotatable shaft having a plurality of floating nutsthreaded thereon, a pawl member disposed to actuate the springmechanism, and a lost-motion device disposed for actuation by saidfloating nuts, when the floating nuts have traveled a predetermineddistance, to operate said pawl.

2. In a switching device, in combination, a switch, an actuating membertherefor, an operating mechanism comprising a rotatable shaft providedwith screw threads, a hollow casing enclosing the operating shaft forcontaining lubricant, a lost-motion connection between the casing andthe actuating memher, and a plurality of floating nuts disposed on saidshaft and having a. lost-motion connection with reference to the casingand said shaft.

3. In a switching device, in combination, a movable switch, an operatingshaft, a plurality of floating nuts threaded on the shaft, means forlimiting the travel of the floating nuts with respect to the operatingshaft, and a pawl for actuating said switch, said pawl being disposedfor operation by the travel limiting means.

4-. In a lost-motion mechanism, a rotatable shaft having a plurality oftraveling threaded nuts mounted thereon, spaced stop members secured tothe shaft, the stop member. being disposed to engage the threaded nut,and means for changing the relation of the distance between saidtravelling nuts and the distance between said stop members, whereby thetravel of said nuts, as limited by said step members, may be adjustedthe travelling nuts in predetermined adjusted positions with referenceto the stop members.

5. In a switching device, in combination, a snap-switch yieldinglymaintained in two operative positions, a rotary actuating n. embertherefor and means for connecting the actuating member to the switchcomprising a ratchet member for moving the switch to either operatingposition and a pawl for actuating the ratchet member to one positionwhen continuously rotated in one direction and actuating the ratchet toanother position when continuously rotated the other direction.

6. In a switching device, in combination, an operating shaft, a floatingnut threaded thereon, stopping means secured to the shaft for engagingthe floating nut, a hollow demountable casing disposed to enclose saidfloating nut and stopping means and adapted to hold a quanti y oflubricating material, means for filling the hollow casing with lubricantand means for permitting automatic lubrication of various parts of thedevice from the supply of lubricant in the hollow casing.

7. In a switching device, in combination, a snap-action switch having anover-center spring, a ratchet mechanism for moving said spring tooperate the switch, a rotating pawl for actuating the ratchet and meansfor connecting the ratchet to the spring so that after the pawl hasactuated the ratchet to operate the switch in one direction the pawl cancontinue to rotate in that same direction without further operating theswitch.

8. In a traveling-nut mechanism, in combination, operating shaft, a pairof adjustable threaded nuts mounted thereon, stopping means for holdingthe nuts from rotating with the operating shafts, means secured to theshaft for engaging said nuts after they have traveled a predetermineddistance, and means for actuating either of the traveling nuts when theymake any contact with the stops secured to the shaft.

9. In a switching device, in combination, a snap-action switch iaving anover-center spring, a. pivot-ally mounted ratchet for dis placing thespring to actuate the switch, a pawl for actua g the ratchet and atravel ing-nut mechanism for actuating the pawl, the traveling-nutmechanism comprising an operating shaft having a pair of threaded nutsmounted thereon and adapted to be adjusted for predetermining the numberof revolutions the operating shaft will make in either direction beforeactuating the pawl, a pair of stop members secured to the shaft forengaging the traveling nuts, a casing for carrying the pawl, said casingenclosing the traveling nuts and stops and disposed to hold the nutsagainst rotation with the operating shaft.

10. In a switch actuating device, in combination, a rotatable shaft, apair of traveling nuts disposed on the shaft and having screwthreadengagement therewith, means for adjusting the nuts to a plurality ofdifferent positions with reference to each other, and means secured tothe shaft for engaging the nuts when they have been actuated apredetermined distance determined by the distance between said nuts.

11. .In a quiclcma-ke and break switch, in combination, a plurality ofpivotally mounted contact members, a plurality of movable contactmembers, over-center spring mechanism for actuating said movable contactmembers from one position to another through an intermediate position ofunstable equilibrium With a snap motion, and means for maintainingpositive contact pressure between said pivotally mounted and movablecontact members until said movable contact members have been actuatedthrough said position of unstable equilibrium.

12. In a switching device, a driving member rotatable about an axis, adriven member rotatable about the same axis as said driving 7 member, apair of nuts freely rotatable with respect to one of said membersandthreaded I thereto, means for preventing rotation of said nuts withrespect to the other'of said members, stop members for limiting theaxial movement of said nuts, a switch, an actuating element for saidswitch, and a lost-motion connection between said driven member and saidactuating element.

In testimony whereof, I have hereunto subscribed my name this fifteenthday of October, 1927 I ANDERS J OHANSSON.

